1. Field of the Invention
The present invention relates to a method for treating a waste gas and an apparatus thereof, and particularly to a method for treating a waste gas and an apparatus thereof capable of reducing the space for establishing the apparatus for treating the waste gas and collecting minute particles formed by oxidizing and cooling the toxic waste gas flown into the apparatus for treating the waste gas through a collecting process without filtering the particles.
2. Description of the Related Art
Recently, industries in the field of computers, information, electricity, etc. have remarkably developed and made a rapid progress. As the base of the development of those industries, the semiconductor industry has greatly contributed to the industries.
Though the development of the semiconductor industry influences on the overall fields of the industries, the possibility of environmental pollution caused by the toxic waste gas which is generated during the process for manufacturing the semiconductor is also immanent.
Reactive gases used in the process of manufacturing the semiconductor are silane, ammonia, oxidized nitrogen, arsine, diboron, boron, trichloride, etc. The above enumerated reactive gases are toxic gases which can injure fatally even when the workers inhale them by accident or they are contacted to the skin of the workers. Only a little of the toxic gas directly participates in the process of manufacturing the semiconductor. The remaining reactive gases are treated by the apparatus for treating the waste gas and then emitted to the air.
In the case that the toxic reactive gas which is not treated exists in the gas which is emitted to the air, the damage caused by the toxic reactive gas to the environment is hard to say.
Accordingly, it is strictly prescribed environmentally and legally to perfectly treat the toxic components having the waste gas before the gases are emitted to the air. Recently, various apparatuses and methods for treating the waste gas generated during the process of manufacturing the semiconductor have been developed.
The conventional methods for treating the waste gas generated during the process of manufacturing the semiconductor includes a wet-type treating method and a dry-type treating method. The above-identified two methods have following problems.
First, the waste gas wet-type treating method will be explained. The toxic component included in the waste gas flown into the reaction chamber having a predetermined hermetic region is reacted chemically with water supplied to the reaction chamber, and thereby water soluble toxic components are collected in forms of deposits or extracted materials. After that, they are discharged to a drain which is formed at a predetermined region of the reaction chamber. This method has a high efficiency in the aspect of treating the toxic components. However, the reaction chamber and the drain are frequently damaged by an reactive solution which is chemically reacted with the water during the treating process.
Moreover, as the reactive solution which has a minute diameter and is scattered and atomized in the reaction chamber is discharged to the exhaust outlet with the vapored waste gas, an exhaust duct is corroded. As a result, it is possible for the waste gas to be leaked from the exhaust duct.
On the other hand, it is essential to retreat the treated reactive solution not to generate the water pollution, thereby resulting in the increase of the cost for treatment.
Owing to the above described problems, another method for treating the waste gas having a different mechanism which is different from the wet-type treating method is required. As a result, a dry-type treating method is introduced.
In the dry-type treating method, the air and the toxic gas are reacted chemically, and they are separated into a polymer which is a solid particle and a refined gas. Here, only the polymers are precipitated and collected.
The dry-type treating apparatus includes: a mixing unit which mixes the waste gas supplied from the semiconductor manufacturing apparatus with non-active gas such as a nitrogen which acts a role in controlling the rapid explosion and an air for combustion reaction; a combustion chamber which supplies an environment of high temperature so that the combustion reaction can be generated in the mixed gas by receiving the mixed gas from the mixing unit; a precipitating chamber which is connected to the combustion chamber so that the second products which are oxidized in the combustion chamber can be cooled and be precipitated in form of the polymer; a collecting chamber which is connected to the precipitating chamber for collecting the precipitated polymers; and a filtering unit for filtering minute polymers which are not collected from the collecting chamber.
However, as the dry-type treating apparatus can partly be stopped up by the minute particles, it is required to dissemble the apparatus to clean the apparatus, and thereby the cost of the apparatus for treating the waste gas can increases due to the costly filter.